In recent years, as electronic devices rapidly become portable and cordless, the desire to increase the capacity of secondary batteries used as power sources for driving the electronic devices increases. Secondary batteries are increasingly used as storage batteries for vehicles and storage batteries for electric power storages. From the perspective of this, there is a need to increase the capacity of the secondary batteries.
Against such a background, for a non-aqueous electrolyte secondary battery in PTL 1, a positive electrode active material slurry is applied to a positive electrode current collector to form a positive electrode active material layer, and subsequently, a rectangular part of the positive electrode active material layer in a plan view is separated. A rectangular exposed portion at which there is no positive electrode active material is formed at a position at which the positive electrode active material layer is separated, and a positive electrode lead is welded to the exposed portion. The width of the exposed portion is less than the width of a positive electrode sheet. This enables the exposed portion to be formed within a portion of the positive electrode sheet in the width direction to increase the region of the positive electrode active material layer. Thus, a region in which charge and discharge reactions occur is increased to achieve an increased capacity.